World of Scientific Discovery on Emil Hermann Fischer
The son of a successful businessman, Emil Fischer, at the urging of his father, reluctantly joined the family firm when he left high school. But the young man yearned to be a mathematician or physicist and, after a few years, his father gave in and allowed him to attend the University of Bonn. A year later, in 1872, Fischer transferred to Strasbourg to study with the well-known chemist, Adolf von Baeyer, and decided to make organic chemistry his career.
After earning his doctorate in 1874 Fischer followed Baeyer to Munich, Germany to continue his studies which, at that time, centered around the organic derivatives of hydrazine (a compound of nitrogen and hydrogen). Many of his hydrazine derivatives later proved highly useful to Germany's dye industry, then in its infancy. More importantly, Fischer discovered that his compounds--phenylhydrazine, in particular--reacted chemically with carbohydrates in such a way that they could be used to separate and identify sugars that, until then, were almost impossible to isolate.
In 1882, Fischer joined the faculty of the University of Erlangen, then moved to Würzburg in 1885. There, he attracted worldwide attention through his continued work with carbohydrates. Using phenylhydrazine as a chemical tool, Fischer was able to isolate a number of pure sugars and to study their structures. He synthesized glucose (the most important simple sugar) and 30 other sugars as well. In addition, Fischer began to study the three-dimensional shape ( stereochemistry) of these sugars and showed that the shapes of the best-known sugar molecules (and perhaps, by extension, the shapes of other classes of molecules) played a greater role in their biochemical activity than their chemical compositions.
Also during the 1880s, Fischer began a study of uric acid and its derivatives. This resulted in the synthesis of a number of important compounds, including the alkaloids caffeine and theobromine. In 1897, Fischer suggested that uric acid and similar substances--substances that were often found in natural products such as urine and feces--might all be derived from a hypothetical parent compound he named purine. A year later, he went on to synthesize purine itself--and, by so doing, opened up a whole new field of research, that of purine chemistry. (Interestingly, purines proved to be part of a group of substances called the nucleic acids, today considered the key compound of living tissues.)
For his work with carbohydrates and purines, Fischer received the Nobel Prize in chemistry in 1902. By then, however, he had already moved on to an investigation into the highly complex, chain-like molecules of proteins. After synthesizing many of the 13 amino acids known, at the time, to be the "building blocks" of protein, Fischer then identified three more amino acids and went on to describe the various ways amino acids combined with each other inside protein molecules. (In general, the amino group of one amino acid becomes tied to the acidic carboxyl group of a second amino acid by a peptide bond.) Moreover, Fisher developed a method for artificially linking amino acids together and, by 1907, succeeded in forming a remarkably authentic polypeptide made up of 18 amino acid units.
In 1903, Fischer also synthesized 5,5-diethylbarbituric acid--the first barbiturate. Barbituric acid, a hypnotic and sedative, found use in the treatment of insomnia and anxiety. Its modern derivatives include the prescription drugs Barbital, Veronal, and Dorminal.
Although he had become one of the world's best-known and most widely respected scientists, Fisher's last years were marked by tragedy. Suffering from cancer, exhausted by the work he did for the German government during World War I, and deeply depressed by the loss of two of his three sons to that war, Fischer took his own life in 1919.
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